Note: Descriptions are shown in the official language in which they were submitted.
3S6
Sizing agent and use -thereof
This invention relates to a sizing agent, which
is based on a hydrophobic, cellulose-reactive sizing
material combined with a fixing and sizing accelerating
agent, and to the use thereof in the production of sized
papers.
The sizing of paper using hydrophobic, cellulose-
reactive sizing agents is known. German Patent NO.
1,148,130 describes aqueous emulsions which contain
ketene dimers -together with amine-modified starch.
German Offenlegungsschrift Mo. 2,951,507 discloses
emulsions which consist of a ketene dimer, an anionic
dispersing agent and a cationic resin, which is obtained
as a reaction product of epichlorohydrin and a polyamino-
polyamide or as a condensate of cyanamide or dicyanamide
and polyalkylene polyamines, and water. German Offenle-
gungsschrift No. 2,710,061 states that the combination of
the polycondensates mentioned with ketene dimer emulsions
improves the sizing action outside the paper-making
machine. German Offenlegungsschrift No. 2,710,060 discloses
the sizing-accelerating effect of reaction products of the
polymer of diallylamine and epichlorohydrin, which,
however, may only be combined with ketene dimer emulsion
in a considerable dilution. German Offenlegungsschrift
No. 2,514,128 describes emulsions which contain a combin-
ation of ketene dimers and polyvinyl pyrrolidone or poly-
vinyl caprolactam, but which also require the simultaneous
use of a fixing agent.
In addition to the hydrophobic cellulose-reactive
sizing agents based on ketene dimers, hydrophobic cellulose-
reactive sizing agents based on anhydrides are also
described, for example in U.S. Patent Nos. 3,582,464 and
3,244,767; and in German Offenlegungsschrift Nos.
2,710,061; 2,947,174 and 2,804,202; also such sizing agents
based on isocyanates (for example, in German Offenlegungs-
schrift No. 2,710,061).
A serious disadvantage of hydrophobic cellulose-
reactive sizing agents is that a fixing and a sizing
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5~
2 --
accelerating agent must also be used in order to achieve
a suitable sizing effect. Another disadvantage, in
particular of sizing with a ketene dimer emulsion, is
that the complete sizing effect is not realised in the
drying stage of the paper-making machine, bu-t only occurs
very slowly outside this machine.
The additives to hydrophobic cellulose-reactive
sizing agents which have been proposed hitherto have been
unable sufficiently to overcome these disadvantages.
Thus, an object of the present invention is the
production of sizing age~ts based on hydrophobic cellulose-
reactive sizing materials which exhibit an improved and
more rapid sizing effect by the use of new fixing agents.
This object is achieved by using as a fixing and
sizing accelerating agent a polymer composed of linear
or branched carbon chains, to which primary, secondary or
tertiary amino and/or quaternary ammonium groups are
bound directly or by side chains.
Thus, the present invention provides a sizing agent
based on hydrophobic, cellulose-reactive sizing materials,
fixing agents and optionally other auxiliaries, character-
ised in that from 1 to 60 parts, by weight, of a fixing
and s i2 ing accelerating agent, and from 0 to 80 parts,
by weight of conventional auxiliaries are used per 10
parts, by weight, of hydrophobic, cellulose-reactive
sizing materials, the fi~ing and sizing accelerating
agent being a polymer composed of linear or branched
carbon chains, to which primary, secondary or tertiary
amino and/or quaternary ammonium groups are bound directly
or by side chains.
The present invention also provides the use of
the above-mentioned sizing agents for sizing paper, in
particular for the pulp sizing of paper.
Hydrophobic, cellulose-reactive sizing agents are
known. Anhydrides, isocyanates and esters are used, the
ketene dimers being particularly useful.
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gL~08856
The following are included as hydrophobic radicals
which carry the reactive groups: alkyl, alkenyl, cycloalkyl,
aryl, aralkyl and alkaryl groups.
Conventional anhydrides include colophonium
anhydride (U.S. Patent No. 3,582,464), anhydrides of the
structure:
Rl -- CO - O - CO - R2
wherein Rl and R2 represent straight- or branched-chain
alkyl, aralkyl or alkaryl radicals having more than
about 14 carbon atoms, and anhydrides of the structure:
R3 - R~ - CO - O - CO
wherein R~ represents a dimethylene or trimethylene radical
and R3 represents a radical selected from alkyl, alkenyl,
aralkyl or aralkenyl radical having more than 7 carbon
atoms, for example substituted cyclic dicarboxylic acid
anhydrides, such as succinic acid anhydride and glutaric
20 acid anhydride, (German Offenlegungsschrift No. 2,710,061),
and oligomers of maleic acid anhydride and polymerisable
olefins, (German Offenlegungsschrift Nos. 2,947,174 and
2,804,202; U.S. Patent No. 3,244,767).
Conventional isocyanates (German Offenlegungsschrift
25 No. 2,710,061) are, for example, those which contain hydro-
carbon radicals having at least 12 carbon atoms, preferably
from 14 to 36 carbon atoms, such as colophonium isocyanate,
hexadecyl isocyanate, octadecyl isocyanate and 6-phenyl-
decyl isocyanate (German Offenlegungsschrift NO. 2,710,061).
Numbered among the esters are the ketene dimers
corresponding to the following general formula:
~
R -C - C
C--C
R -CH
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wherein R5 and R6 represent hydrocarbon radicals having
from 8 to 30 carbon atoms which may also contain unsatur-
ated and/or cyclic hydrocarbon groups, for example satur-
ated or unsaturated alkyl, aralkyl, alkylaryl or alkyl-
cycloalkyl groups. Commercially valuable ketene dimersare obtained from fatty acids having from 12 to 22, in
particular from 14 to 20, car~on atoms. Commercial fa~ty
acid mixtures, such as commercial stearic acid, are partic-
ularly suitable which contain as the main component stearic
and palmitic acid, and fatty acid mixtures which are derived
from naturally occurring fats, for example coconut oil,
babassu oil, palm kernel oil, palm oil, olive oil,
arachis oil, rapeseed oil, ~eef tallow, lard and whale
blubber.The ketene dimers are produced from the fatty acids
via the corresponding fatty acid chlorides, from which
ketene dimers may be obtained by reaction with tertiary
amines by the release of hydrogen chloride.
The new fixing and sizing accelerating agents are
produced by homo-, co or graft polymerising vinyl compounds
containing amino and/or ammonium groups by themselves or
combined with other vinyl compounds, or by introducing
amino groups into homo-, co- or graft polymers, for
example by reacting homo-, co- or graft polymers which
contain reactive groups with diamines, one amino group
o~ which is a primary or secondary amino group, or by
amino-formylating in a known manner homo-, co- or graft
polymers containing amide groups, or by splitting off the
protective groups from homo~, co- or graft polymers which
contain protected amino groups, or by quaternising in a
known manner homo-, co- or graft polymers having tertiary
amino groups.
The following are examples of monomers containing
amino groups: N,N-dialkyl-aminoalkyl(meth)acrylates and
N,N-dialkyl-aminoalkyl(meth)acrylamides, such as N,N-
dimethyl-aminoethylacrylate, N,N-dimethyl-aminoethyl
methacrylate, N,N-diethyl-aminoethyl acrylate, N,N-
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dlethyl- aminoethyl methacrylate, N,N-dimethyl-aminoethyl
acrylamide, N,N-dimethyl-aminoethyl methacrylamide, N,N-
diethyl~aminoethylacrylamide, N,N-diethyl-aminoethyl
methacrylamide, 2-vinyl pyridine, 4-vinyl pyridine, N-
vinyl imidazole and methyl-substituted N-vinyl imidazoles
and N,N-disubstituted vinyl benzylamines and ~-dialkyl-
aminoethyl styrenes. N,N-dimethyl-aminoethyl acrylate,
N,N-dimethyl-aminoethyl methacrylate, N,N-dimethyl-amino-
ethyl acrylamide and N,N-dimethyl-aminoethyl methacrylamide
are pre~erred. The first two acrylates mentioned a~e
particularly suitable.
Monomers introducing ammonium groups may be
obtained by reacting the above-mentioned monomers containing
amino groups with conventional quaternising agents. The
following are mentioned as examples: trimethylammonium-
ethyl(meth)acrylate, trimethylammonium-ethyl(meth)acryl-
amide and N,N-dimethyl-N-(2,3-epoxypropyl)-ammonium-ethyl
(methacrylamide), N,N-dimethyl-N-(2,3-epoxypropyl)-ammonium-
ethyl(meth)acrylate, N,N-dimethyl-N-(3-chloro-2-hydroxy-
propyl)ethyl ammonium(meth)acrylamide and N,N~dimethyl-N-
(3-chloro-2~hydroxypropyl)ethylammonium(meth)acrylate.
Anhydride, ester, amide, nitrile and haloalkyl
groups are mentioned as reactive groups which may be partly
or completely reacted with diamines in known manner in a
secondary reaction. They may be introduced by means of
monomers, such as maleic acid anhydride, methyl acrylate,
methyl methacrylate, acrylic acid anhydride, chloroethyl
vinyl ether and ~-chloro-methyl styrene.
Diamines which are sui-table for the reactions
with the reactive groups include the ~ollowing, ~or
example: N,N-dimethylaminopropylamine, N,N-dimethylamino-
ethylamine, N,N~diethylaminopropylamine~ N,N-diethylamino-
ethylamine, N-(aminoethyl)piperazine and N-(aminopropyl)-
piperazine.
Monomers which contain protected amino groups
from which the amino groups are completely or partly
released in a known manner only a~ter polymerisation,
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include vinyl amides, such as N-vinyl formamide, N-
methyl-N-vinyl formamide, N-vinyl acetamide and N-methyl-
N-vinyl acetamide, vinyl imides, for example N-vinyl
succinimide and N-vinyl phthalimide, N-vinyl carbamic
acid esters, for example O-t-butyl-N-vinyl carbonate and
O-methyl-N-vinyl carbamate.
Monomers which may be co- or graft polymerised
with the above-mentioned monomers introducing amino groups
are those which result in hydrophobic fragments in co- or
graft polymers, for example olefins, such as ethylene,
propylene, isobutylene and diisobutylene, dienes, such as
butadiene and isoprene, vinyl compounds, such as styrene,
~-~m- or o-methyl styrene, u-methyl styrene and p-, m-
or o-chloro styrene, vinyl ethers, vinyl esters, such as
vinyl acetate, vinyl chloride, vinylidene chloride, (meth)-
acrylates, such as methyl methacrylate, ethyl methacrylate,
n-butyl methacrylate, methyl acrylate, ethyl acrylate,
n-butyl acrylate and 2-ethylhexyl acrylate, acrylonitrile
and methacrylonitrile.
Copolymerisation may take place in substance or
preferably in solution, and may be carried out discontin-
uously or continuously, or by the monomer supply process.
Continuous and monomer supply processes are particularly
preferred.
In the latter type of process, the solvent is intro-
duced, adjusted to the polymerisation temperature and the
monomer mixture is added dropwise into the solvent at the
same time as the initiator. The mixture is re-activated
after some time, and the reaction is completed up to a
30 conversion of from about 99.0 to 99.9%.
The polymerisation temperature may range from 50
to 150C, preferably from 60 to 100C. Of course, it
depends on the type of initiator which is used and on the
half-life thereof.
R~dical-formirlg compounds which are conventional
for initiating polymerisations are included, for example
azo compounds, such as azoisobutyronitrile, or peroxides,
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'8856
such as t butyl-perpivalate, t-butyl-per-2-ethylhexanoate,
benzoyl peroxide, t-butyl perbenzoate, di-t-bu-tyl peroxide
and cumene hydroperoxide. They are cJenerally used in quan-tities
of from 0.1 to 6~, by weight, based on the initial
monomer mixture. Quantities of from 0.5 to 4~, by weight,
are preferred.
~ ater or water-miscible and non-water-miscible organic
solvents are included as a rteaction medium for the poly-
merisation in solution. The following are suitable for
this purpose: alcohols, such as ethanol and isopropanol,
ketones, such as acetone, ethylmethyl ketone and methyl-
isobutyl ketone, esters, such as methylglycol acetate
dioxane, N-dimethyl formamide and aromatics, such as
benzene, toluene and xylene.
A polymerisation in a high solution concentration
of from about 50 to 90%, by weight, of the final polymer
is recommended to prevent as far as possible the intro-
duction of solvent into the final aqueous solution. After
polymerisation, the N,N-dialkylamino groups may be
quaternised, advantageously in the solvent which has
already been used for polymerisation.
The following are included as suitable quater-
nising agents, for example: alkyl and aralkyl halides~
such as methyl chloride, methyl bromide, butyl bromide
and benzyl chloride, o-ther halogen compounds, such as
propargylchloride, allyl chloride and chloroacetic
acid ethyl ester, epihalohydrins, such as epichloro-
hydrin and epibromohydrin, sui-table esters, such as
dimethyl sulphate and p-toluene sulphonic acid methyl
ester, and epoxides, such as ethylene oxide and propylene
oxide.
It is also possible to use mixtures of these
quaternising agents. Epihalohydrins are preferred,
particularly epichlorohydrin.
The quaternising agents are added to the polymer
solutions in quantities such that Erom 0.1 to 2~0 moles
of quaternising agent are produced permole equivalent
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5~;
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amino group. ~ol ratios of ~rom l:0.2 to l:l.2 (amino
group:quaternising agent) are preferred. Quaternisation
takes place at a temperature of from 25 to 160C, pre-
erably from 40 to 80C. The reaction generally lasts fr~n 0.5 to
lO hours.
In order to obtain water-soluble cationic polymers,
water-soluble organic or inorganic acids are also added
which protonate the non-quaternised free amino groups.
The following are included as acids: formic acid, acetic
acid, propionic acid, iactic acid, hydrochloric acid,
nitric acid, sulphuric acid and phosphoric acid. Formic
acid, acetic acid and hydrochloric acid are particularly
preferred. The acids are added in quantities of from 50
to 500 mol %, based on the tertiary amino groups bound in
the polymer. A quantity of from lO0 to 300 mol ~ of acid
is preferred. If epichlorohydrin is usedas the quater-
nlsing agent, polyadditions and gelling reactions resulting
therefrom are simultaneously interrupted by adding the
acids.
Water is generally used as solvent for the poly-
cations. After the polymers have been dissolved in the
water, from about lO to 3~, by weight, preferably from
15 to 25% by weight, solutions are present. The organic
solvents which are still contained therein should be
removed by distillation if they react with the reactive
sizing agent, or if they do not form homogeneous mixtures
with water. Alcohols and aromatics and longer-chain
ketones, in particular, come into this category.
Those homo-, co or graft polymers which are
composed of hydrophobic and hydrophilic monomer units are
preferred, and the ratio of hydrophobic to hydrophilic
monomer units is selected such that water-emulsifiable
or water-soluble polymers are obtained.
The following are preferred as fixing and sizing
accelerating agents: in particular copolymers of N,N-
dialkylamino--alkyl(meth)acrylates and/or amides and/or
alkyl(meth)acrylates, styrene, isobutylene, diisobutylene,
Le A 21 287
56
vinyl acetate and/or acrylonitrile; also reaction products
of copolymers of maleic acid anhydride and styrene and/or
diisobutylene with a mixture of from 0 to 50 mol % of
methylamine, ethylamine, propylamine, butylamine and/or
cyclohexylamine and from lO0 to 50 mol % (based on the
primary amino group) of N,N-dimethyl-aminopropylamine
and/or N-(~minoethyl)-piperazine and subsequent quater-
nisation up to a quaternisation degree of from 0 -to lO0~,
also, the products of partial hydrolysis of copolymers of
Ncvinyl acetamide, N-methyl-N-vinyl acetamide or O-methyl-
N-vinyl carbamate and vinyl acetate.
Fixing and sizing accelerating agents which are
particularly preerred include statistical terpolymers
which are composed in a chemically uniform manner, i.e.
are of as low a heterogeneity as possible, consisting
of the following:
(a) from 8 to 20%, by weight, of N,N-dimethyl-aminoethyl
acrylate and/or N,N-dimethyl-aminoethyl methacrylate;
(b) from 45 to 80%, by weight, of styrene; and
(c) from 8 to 35%, by weight, of acrylonitrile,
and the dimethylamino groups of the terpolymer being
protonated, and optionally also partly or completely
quaternised.
The heterogeneity of the chemical composition may
be determined by taking a sample during polymerisation
and then determining the composition by elementary analysis,
by O~I number determination etc. It is also possible to
characterise the chemical heterogeneity by precipitation
fractionation, for example using the solvent/precipitant
system of acerone/petroleum ether. The heterogeneity
parameters ~`-i which are calculated by the measured co-
polymerisation parameters ar~d are also found experimentally
range from 0 to 0.06, preferably from O.Ol to 0.05.
The C~ i parameters are defined for each comonomer in the
copolymer. -i is a measurement for the scattering and
is defined in the literature (H.G. Elias, Makromol. Chem.
04 (1967), P. l~
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The advantage of such copolymers is a very good
water~solubility even with a very low content of basic
comonomers and an outstanding emulsifier effect.
In the context of the present invention, the
term "auxiliaries" is to be understood as designating
the following, for example: emulsifiers, solvents,
thickeners, biocides, such as fungicides,and anti-foaming
agents.
The emulsions are produced, for example, by
dispersing the hydrophobic cellulose-reactive sizing
material, to which from about 5 to 35% by weight of a liquid
hydrocarbon, such as toluene, cyclohexane and octane, or
hydrocarbon mixtures may be added, in water at a tempera-
ture of from 30 to 90C. The following may be used as
emulsifiers; for example: anionic dispersing agents
selected from cresol-naphthol sulphonic acid-formaldehyde
condensates or phenol-bisulphite urea condensates,
non-ionic emulsifiers obtained by adding ethylene oxide
to hydroxyl groups, and compounds containing relatively
long hydrocarbon radicals, such as saturated and
unsaturated alcohols having from 12 to 18 carbon atoms,
or alkylated phenols, starches and combinations of
two or more of the emulsifiers mentioned. A combination
of anionic dispersing agents with cationically-modified
starch is preferred. The guantities of emulsifiers are
calculated such that emulsions are obtained ~hich
are stable for a long time and this is within the
experience of those skilled in the art. The stability
of the aqueous emulsions may be considerably increased
by making an adjustment to an acid pH. A pH of from
2.0 to 5.5, preferably from 3.0 to 4.5 is usually
adjusted using mineral acid or Cl-C4 carboxylic acids.
To produce the new sizing agent, one of the
above-described emulsions is intensively mixed with an
adequate quantity of the fixing and sizing accelera-ting
agent to increase the sizing effect of the sizing material.
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It has been found that from 0.l to 6 parts, by weigh-t,
per part, by weight, of the hydrophobic cellulose-
reactive sizing material in the emulsion leads to yood
results. A quantity of from 0.25 to 4 parts, ~y weight,
is preferred.
It may be advantageous directly to disperse the
sizing material in an aqueous dispersion or solution of
the polymer and to dispense wi-th the addition of
emulsifiersO
In order to increase thestorage stability, the
emulsion may contain -thickeners, for example starch
derivatives, cellulose derivatives~ polycarboxylic
acids, and polysulphonic acids.
The sizing agents according to the present
invention contain generally from 2 to 10%, by weight, of hydrophobic
reactive sizing material (based on the total sizing
agent).
Compared to the prior art (polycondensates), it
has surprisingly been found that the sizing effect of
the hydrophobic cellulose-reactive sizing material, in
particular of ketene dimers, may be considerablv
increased even by such an added ~uantity of water-soluble
cationic copolymer which, taken on its own, does not
e~hibit a significant sizing effect when used in paper
pulp. It was also unforseeable that an almost complete
realisation of sizing effect may be achieved by the
water-soluble cationic polymer which is added even at
drying temperatures of 90C. With respect to compara-
tive products according to German Offenlegungsschrift No.
2,951,507, the realisation of the sizing effec-t is
clearly improved.
Example l
Production of the cationic fixing and sizing accelerating
agents (A-F)
50 g of isopropanol are introduced into a 2 litre
flask equipped with a stirrer, a reflux c~n~n~r and a gas
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- 12 -
inlet and outlet. The flask is then thoroughly ~lushed
with nitrogen and heated to 80C. The mixtures I and the
solutions II of Table I are metered in at this temperature
over a period of 2 hours with the exclusion of air. The
mixture is then stirred for ~ hours and re-activated with
III. Thereupon, it is stirred for 12 hours at 80C~
After polymerisation, the mixture is cooled to
the temperatures specified in Table I and the quantities
of quaternising agents (IV) specified in the ~able are
metered in. The mixture is then stirred for 3 hours and
subsequently mixed with the quantities of acetic acid
which are also stated in Table I. At the same time,
enough deionised water is added to the mixture for an
approximately 20%, by weight, solution to be produced.
The solution is then stirred until a homogeneous aqueous
solution results. From 100 to 150 g of organic solvent
and water are distilled off under a water jet vacuum.
The residual contents of acetone and isopropanol are
then clearly below 0.5% by weigh~. The quantity distilled
off is then replaced by deionised water.
The aqueous solutions have the properties which
are also indicated in Table 1.
Production of the fixing and sizing accelerating agents
G and H
25 G) 123 g of copolymer of the same molar proportions
of isobutylene and maleic acid anhydride are
heated to 90C for 1 hour in an autoclave with
1 g of polyvinyl alcohol and 90 g of 3-dimethyl-
aminopropylamine under ni-trogen and then heated
at 100C for 3 hours. After cooling, the solids
are centrifuged off, washed and dried. To produce
the emulsion, a 10% by weight ~ o1-~ solution of the
polymer at pH 3 (hydrochloric acid) is prepared.
H) 6U g of copolymer of 30 mol % of O-methyl-N-vinyl
carbamate and 70 mol% of vinyl acetate were heated
at 80C for 15 hours in 300 g of 5~ aqueous
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hydrochloric acid. The cooled solution had a
solids content of 12.5% and the polymer had a
~ntr1n~-~ viscosity number " = 1.70 dl/g
(0O9% NaCl solution).
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Table I
Accelerating agents A B C D E F
Polymerisation temperature [C3 80 80 80 80 80 80
Quaternisation temperature [C] 40 40 50 40 40 40
I. N,N-dimethyl-aminoethyl-methacrylate [g] 27.3 33.8 28 28 28 28
Styrene [g] 78.4 87.1 89 89 89 89
Methyl methacrylate ~g] - 48.4
Acrylonitrile [g] - - 23 23 23 23
_-butyl acrylate [g] 29.7 - - - - -
II. . Azoisobutyronitrile [g] 4 4.4 5 5 5 5
Acetone [g~ 20 22 26 22 22 22
III. Azoisobutyronitrile [g] 1 1 0.6 0.5 0.5 0.5
Acetone [g] 5 5 2~6 3 3 3
IV. Chloroacetic acid ethyl ester [g] - - 16.4 - - -
Epichlorohydrin [g] 16.1 19.9 - - 5.5 11
V. Acetic acid [g] 20 25 20 20 20 20
Concentration [~, by weight] 19.6 23.1 20~7 19.0 20.0 22.2
Viscosity (at 20C) [mPa.s] 235 155 - 50 50 50
pH 3.9 3.9 3.0 4.0 4.0 4.2
- 15 -
Example 2
Production of ketene dimer emulsions (embodiment A)
A mixture of 300 g of cationic potato starch,
25 g of acetic acid and 4675 g of water was stirred for
l hour at from 90 to 95C. The mixture was cooled to
60C 600 g of ketene dimer, produced from a mixture of
palmitic acid and stearic acid and 25 g of anionic
dispersing agent (A) phenol-bisulphite-urea condensate
or (B) cresol-naphthol sulphonic acid-formaldehyde
condensate were stirred in using a high-speed stirrer,
and the mixture was passed twice through a Knollenberg
homogeniser under a pressure of 200 bars. The hom-
genised product was diluted with water to a ketene dimer
content of 7.7% by weight, and cooled to 30~. The solution of the
fixing and sizing accelerating agent was added at this
temperature, and diluted with water to a ketene dimer
content of 6% by weight.
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~!L2~ 5~
- 16 -
~ ) 0~o 0~o OP 0\o 0~o 0~o 0~o 0~o 0~o 0~o, 0~o 0~o 0~o
'
~:~ooooooooooooo
~ u
.~ .,
n~
o
~ U~
n
~1
~ '
Q, 1
'
~c
:) O'P 0~ OP OP 0~ 0~ OP O~P O\P OP O~P 0~ 0~
~ u ~ ~ ~ o
o ~
! I ~r --1 0 0
4~ r--
U
~C
U
~1
H
H C td ~ C) ~ IJ 4~ rl ~ r~
a~ ¢
r-l r
.q -
E~ ~
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~L2~ 56
- 17 -
Example 3
Ketene dimer emulsion (embodiment B)
A 6 ~, by weight, aqueous solution of cationic
starch was produced as described in Example 2. In each
case, a parts of the starch solution, _ parts of disper-
sing agent A, c parts of acetic acicl, d parts of the
polymer solution F and e parts of water were mixed.
f parts of a molten ketene dimer, produced from a mixture
of palmitic acid and stearic acid, are stirred into this
mixture at a temperature of from 60 to 65C using a
high-speed stirrer and the mixture is passed twice through
a Knollenberg homogeniser under a pressure of 200 bars.
The homogenised sample was diluted with water to a ketene
dimer content of 6% by weight and cooled to 30C.
Table 3
Emulsion a b c d e f
3a - lO - 400 400 60
b 300 7 5 60 lO0 60
c 400 7 5 60 - 60
d 300 7 5 - lO0 60
e 400 - 5 60 - 60
f 400 - 5 200 60
g - -( ) 5 900 - 60
h - -( ) 5 250 - 60
25 (+)
20 parts of emulsifier (from 1 mol nonylphenol and
10 mols of ethylene oxide).
Example 4
Sheets of paper are produced on a laboratory
sheet forming machine, using the sizing agent emulsions
of Examples 2 and 3. A pulp having a solids content
of 0.5% was produced in water with a hardness of about 20 dH frcm 100
of wood pulp (50~ birch sulphate, 50% pine sulphate)
having a degree of grinding of 30 SR, and 25 parts of
chalk. 1.4 %, based on the dry weight of the pulp, of
emulsion was added. The resulting sheets were wet
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pressed to a solids content of from 30 to 35~, and then
dried for 4 minutes at from 90 to 93C on a steam
heated drum dryer.
The sheets of paper had a weight per unit area of 80
g/m . A fixing agent was not used.
The Cobb60 va]ue (DIN 53 132) was determined in
order to establish the sizing effect. Some papers were
also re-heated for 5 minutes at 120C, or stored for
7 days at 22C.
Table 4 Emulsion
Example according to Example Cobb60
4a 2a 28
b 2b 31
c 2c 29
d 2d 30
e 2e 24
f 2f 22
g 2g 23
h 2h 26
i 2i 29
k 2j 38
1 3a 30
m 3b 21
n 3c 22
O 3d 75
p 3e 26
3f 28
r 3g 30
s 3h 31
t 2f 20 (rehea-ted for
5 mins at 120C)
u 2f 22 (stored for 7
days at 20C)
~ 21 25
w 2m 23
Le A 21 287
/
